1. Field of the Invention
The invention relates to a device for securing a mixing capsule for dental preparations to the support of a vibrating machine for mixing the components of said dental preparations, said support being provided with an abutment and a presser adjustable by an operating lever pivoted to said support, said abutment and said presser being adapted to secure said mixing capsule in a first position of said presser and to release said mixing capsule in a second position of said presser.
2. Discussion of the Prior Art
To mix dental preparations consisting of at least two components, such as amalgam, vibrating machines are known which can vibrate one mixing capsule at a time at a high frequency for a predetermined time; the various components experience thorough mixing to give an end product in the form of a tooth filling composition. Most of the known vibrating machine constructions comprise a rocking arm having two spring strips arranged like a fork, the spring strip ends having holders or the like for the capsule as shown e.g. in the U.S. Pat. No. 3,222,037. The swing arm is mounted at one end and can be vibrated multidimensionally by one-dimensional or multi-dimensional eccentric drives; preferred directions of vibration can be determined by the mounting of the swing arm and by the use of at least one stabilizing spring.
It is also known to provide a carrier or support for the mixing capsule on the swing arm. The carrier has a stationary abutment and an adjustable presser which either takes the form of an adjusting screw to press the mixing capsule towards the abutment or is a two-armed lever, one arm of which presses on one end of the capsule when the other arm experiences a corresponding lever-pivoting force. For this purpose, the other lever arm of the known device has a sliding surface engaged by an eccentric secured by way of an operating lever to a spindle rotatably mounted on the carrier or support. The capsule is placed against the abutment to locate it, whereafter the two-armed lever pivots towards the other end of the capsule, and when the operating or control lever is pressed down manually, the eccentric presses against the sliding surface on the other arm of the two-armed lever until the capsule has been located on the carrier or support. The tightness of the securing or clamping depends upon frictional engagement between the eccentric and the sliding surface. The frictional engagement is increased by the weight of the actuating or operating lever. However, this is no guarantee of the capsule continuing to remain located when subjected to multidimensional vibratory motion. The operating lever itself has a considerable mass which can make natural vibrations, which can lead to the two-armed lever working loose or to the location of the capsule becoming ever tighter as a result of the eccentric becoming wedged more strongly relatively to the sliding surface. This may lead after prolonged use to a damage of the sliding surface and to the eccentric contact surface, and once the damage has occurred considerable clearance rapidly arises, making it impossible to locate the capsule satisfactorily and to remove the capsule from the support. The difficulty of removal is a particular disadvantage since the prepared filling should be applied very rapidly.
Another disadvantage of the known vibrating machines for mixing dental preparations is that, in the case of mixing capsules in which one component for the mix, e.g. mercury, is placed in a shallow pad-like foil bag or the like whose contents are introduced into the mixing chamber by adjustment of a cap relatively to the mixing capsule immediately before mixing, an extra appliance is required to open and empty the foil bag, and since considerable forces are required to make sure that the bag is emptied completely, the usual practice is to use a table appliance having a long enough lever arm to move the cap relatively to the capsule. The mixing capsule, which by now contains all the components in its mixing chamber, must then be inserted into and secured or located in the vibrating machine, special care being necessary to prevent any exit of mercury or mercury vapors during the preparation of amalgam fillings.
It is an object of this invention to provide a device enabling mixing capsules to be secured, with a tightness which remains constant, to the vibrating machine support so as to facilitate the individual mixing operation and to increase the working life of the system. Also, in the case of mixing capsules in which one component is stored in a foil bag, the manner in which the force is applied is such that the bag can be opened during the location of the capsule and the bag contents introduced into the capsule mixing chamber, thus obviating the need for the conventional extra appliance.